A drug suspect was taken to a federal holding facility and “accidentally left in one of the cells” last month until he was found with methamphetamines and taken to the hospital, the Drug Enforcement Administration said Monday.

The suspect was “left” on April 21, according to the agency. The paramedics were called on April 25, the San Diego Fire-Rescue Department confirmed.

The DEA was not answering questions on Monday about what happened in the five days in between: Did the suspect have food and water and a toilet? How did he get methamphetamines while in custody?

Spokeswoman Amy Roderick said such matters are under investigation. She promised a thorough review of detention procedures and the events of April 21 and after.

The DEA said Monday that the suspect was one of nine people detained April 21 following a drug raid that yielded 18,000 ecstasy pills, marijuana, hallucinogenic mushrooms, a Russian rifle, two handguns and thousands of rounds of ammunition.

Roderick said all of the detainees were brought to the DEA field office at an office building in Kearny Mesa, where they were questioned, fingerprinted and photographed.

“Each suspect was interviewed in separate interview rooms, and frequently moved around between rooms and cells,” Roderick said.“All suspects were searched incident to arrest, but none were strip or body cavity searched.”

She said seven suspects were brought to the county jail, one was released “and the individual in question was accidentally left in one of the cells.”

The statement then skips to when the detainee was discovered.

“When agents found the individual in question, they were told by the individual that he had used a white powdery substance that he found in the cell,” Roderick said. “The agents who found the young man in question called EMS, and field tested the substance, which tested positive for methamphetamine.”

San Diego city paramedics were summoned to the San Diego DEA field office on Viewridge Avenue about 4:40 p.m. Wednesday.

“Report was a 24-year-old man in a holding cell said he took white powder substance,” San Diego Fire-Rescue spokesman Maurice Luque said. “He was conscious. He was transported to Sharp in non-life-threatening condition.”

The location of the raid was not provided. Roderick said the man admitted to being at a house “to get high with his friends.”

The man is a student at the University of California San Diego. He was reported missing by his roommate last Friday, two days after he was taken to the hospital, UCSD police said. Campus police said the man notified officers on Saturday that he was OK and the missing-persons report was canceled.

He offered no details about where he had been over the previous week, and simply wanted the missing-person case closed, UCSD Police Chief Orville King said.

It is not clear whether the man will face any criminal charges related to the drug raid, but the DEA said he is not under arrest.